GRAINS-Soy up 1 pct, bounces from 4-week low; corn firm

* Soy up over 1 pct on investor buying, dollar

* Corn, wheat rise on spillover strength from soybeans

* Ideal U.S. Midwest weather caps gains (Adds details, quotes)

SINGAPORE, Aug 18 - U.S. soybeans rose more than 1 percent on Tuesday, regaining some ground after sliding to a four-week low, as investors bought back into the oversold market and dollar weakness supported commodities.

Corn also firmed, but gains were in Chicago grain markets were capped by expectations of near-record crops, given the greenhouse-like weather conditions across the U.S. Midwest.

"We are seeing buying today in line with a bit of U.S. dollar weakness," said Garry Booth, a trader with MF Global Australia.

"Of course there are some concerns about the pace of Chinese soybean buying and good weather in the United States."

On Monday, soybeans fell 4 percent, while corn lost 1.5 percent to trade at a 3-½ week low on perfect weather and renewed global economic concerns.

Daily episodes of showers and warm temperatures will continue across the U.S. Midwest over the next week, providing favourable conditions for maturing corn and soybeans, a forecaster said.

Corn yields in Ohio were projected to rise 7.4 percent but the crop needs some rain during the last few weeks of the growing season to reach its full potential, scouts on an annual tour found.

Soybean and corn crops were planted late this year in the United States, leading to some concerns about the fate of crop production. But the weather patterns have turned nearly perfect for plant development.

New-crop November soybean futures rose nearly 1 percent to $9.62-½ a bushel by 0327 GMT and the front-month September contract gained 1 percent to $9.75 a bushel.

September corn rose 0.6 percent to $3.16 a bushel.

Weakness in the cash soybean prices also weighed on futures as the market expected that old-crop supplies might not be as tight as anticipated earlier.

Spot cash soybean prices around the U.S. Midwest have plunged over the past two days as fears are fading that the existing stockpile of soybeans would run short before the freshly harvested supplies become available.

Cash soybean prices ballooned to more than $12 a bushel this summer after the U.S. Agriculture Department projected soybean stocks would fall to a 32-year low of 110 million bushels by the end of the current marketing year on Aug. 31.

Analysts are also concerned about China's soybean demand in the months ahead as the country has started auctioning record stockpiles, even though interest in government's reserve sales has been poor in the initial rounds. China, the world's top soybean importer, will hold another round on Wednesday to sell some 500,000 tonnes from stocks estimated at 6 million tonnes.

Wheat futures rose, but the market continues to hover around 8-month lows, under pressure from global oversupply and poor demand for U.S. wheat. September wheat rose 0.5 percent to $4.74 a bushel. PRICES AT 0327 GMT Contract Last Change Pct chg Day ago pct MA 30 RSI CBOT wheat 474.00 2.25 +0.48% -1.61% 511.01 35 CBOT corn 316.00 1.75 +0.56% -1.02% 329.88 40 CBOT soy 997.75 9.75 +0.99% -9.30% 1091.49 35 CBOT rice $13.30 $0.01 +0.08% -0.04% $13.38 47 WTI crude $67.04 $0.29 +0.43% -0.70%

$66.38 47 Currencies

Euro/dlr $1.410 $0.003 +0.20% -0.51% USD/AUD 0.823 0.002 +0.22% -0.76% Front month contracts Wheat, corn and soy US cents/bushel. Rice: USD per hundredweight